The regulation of postprandial thermogenesis
Research type
Research Study
Full title
The use of intranasal insulin as a tool to investigate postprandial thermogenesis in women with obesity and polycystic ovary syndrome.
IRAS ID
311406
Contact name
W. Colin Duncan
Contact email
Sponsor organisation
University of Edinburgh
Duration of Study in the UK
2 years, 0 months, 31 days
Research summary
Polycystic ovary syndrome (PCOS) is a common condition that affects 1 in every 12 women. It is associated with a hormone imbalance that causes irregular periods and difficulty in getting pregnant. However, a major concern for those with PCOS is their difficulty in maintaining a healthy weight. Women with PCOS are more likely to be obese, obesity makes the features of PCOS worse and weight loss improves PCOS. However, women with PCOS find losing weight difficult. This is because they are less able to burn calories after eating. This process is called postprandial thermogenesis. It is the result of increased nerve signals from the brain to tissues, such as fat, after eating and women with PCOS burn 25% less calories than weight-matched controls. A better understanding of this process could lead to new treatments to normalise energy expenditure in PCOS and facilitate weight loss.
We have discovered that this might be due to reduced signalling of the hormone insulin in the brain after eating. This experimental study with humans is designed to determine whether raising insulin levels in the brain using an intranasal spray improves energy expenditure after eating in obese women with PCOS. We will also determine if the effect is PCOS-specific and look in detail at subcutaneous fat cells.
The participants will be obese women with (n=12) and without (n=12) PCOS identified through the reproductive medicine clinics in Edinburgh. They will attend the clinical research facility on two separate mornings. Energy expenditure, assessed by indirect calorimetry, will be measured after being fed a standard meal. On one occasion they will be given intranasal placebo and on the other intranasal insulin in random order. We will collect microdialysis fluid and a small biopsy from the fat under the skin of the tummy to examine in the laboratory.
REC name
West of Scotland REC 5
REC reference
22/WS/0032
Date of REC Opinion
5 Apr 2022
REC opinion
Further Information Favourable Opinion